Tuberculous bursitis of the greater trochanter mimicking ankylosing spondylitis.

Tuberculous trochanteric bursitis (TTB) is a rare condition that accounts for 1% of musculoskeletal tuberculosis cases. Extrapulmonary TB is usually diagnosed late because of reduced diagnostic suspicion, particularly in the absence of signs of systemic infection. Herein, we report a case of right hip pain that was misdiagnosed as ankylosing spondylitis. The patient had a history of inflammatory back pain with morning stiffness. However, HLA-B27 was negative. Sacroiliac magnetic resonance imaging (MRI) revealed a giant multiloculated collection (27×16×10 cm). Percutaneous drainage was performed and Mycobacterium tuberculosis was observed in fluid culture. The patient was treated by drainage along with antituberculosis therapy. After 1 year of antituberculosis therapy, control MRI revealed total resolution of the large fluid collection. It is important to emphasize that fever or general symptoms are absent in patients with TTB, as observed in the present case. In endemic countries, TTB should be kept in mind in the differential diagnosis of a patient presenting with chronic hip pain without fever, weight loss, and constitutional symptoms.